Degradation of cellulose by basidiomycetous fungi

Abstract

Cellulose is the main polymeric component of the plant cell wall, the most abundant polysaccharide on Earth, and an important renewable resource. Basidiomycetous fungi belong to its most potent degraders because many species grow on dead wood or litter, in environment rich in cellulose. Fungal cellulolytic systems differ from the complex cellulolytic systems of bacteria. For the degradation of cellulose, basidiomycetes utilize a set of hydrolytic enzymes typically composed of endoglucanase, cellobiohydrolase and beta-glucosidase. In some species, the absence of cellobiohydrolase is substituted by the production of processive endoglucanases combining the properties of both of these enzymes. In addition, systems producing hydroxyl radicals based on cellobiose dehydrogenase, quinone redox cycling or glycopeptide-based Fenton reaction are involved in the degradation of several plant cell wall components, including cellulose. The complete cellulolytic complex used by a single fungal species is typically composed of more than one of the above mechanisms that contribute to the utilization of cellulose as a source of carbon or energy or degrade it to ensure fast substrate colonization. The efficiency and regulation of cellulose degradation differs among wood-rotting, litter-decomposing, mycorrhizal or plant pathogenic fungi and yeasts due to the different roles of cellulose degradation in the physiology and ecology of the individual groups.

Mode of action of brown rot decay resistance in modified wood: a review

“…The first signs of brown rot decay are visible in the outer regions of the cell wall, that is, in the middle lamella, S1, and the outer parts of S2 (Irbe et al 2006;Fackler et al 2010 Goodell et al (1997), Arantes et al (2012), and Baldrian and Valaskova (2008). HQ, hydroquinone; MF, microfibrils; Q, quinone.…”

“…Details of polysaccharide degradation by brown rot are summarized in Figure 1, which is based mainly on studies by Goodell et al (1997), Baldrian and Valaskova (2008), and Arantes et al (2012). Brown rot fungi degrade polysaccharides via oxidative and enzymatic activities (Eriksson et al 1990;Eaton and Hale 1993;Goodell 2003;Aro et al 2005;Fackler et al 2010).…”

“…Decay resistance has been reviewed independently for acetylated wood (Papadopoulos 2010) and thermally modified wood (Esteves and Pereira 2009) as well as in a combined review (Rowell et al 2009). Previous research concerning the degradation of cellulose by brown rot fungi was summarized by Baldrian and Valaskova (2008). Aro et al (2005) reviewed the transcriptional regulation of enzymes involved in the breakdown of cell wall biopolymers by filamentous fungi.…”

ENZYMATIC EXTRACT OF Trametes maxima CU1 ON PRODUCTIVE PARAMETERS AND CARCASS YIELD OF RABBITS

“…Others have tested Ganoderma resinaceum for the degradation of the cell wall components of olive lives trying to increase rabbit productivity (Ribeiro et al 2012), and the most recent use of cellulases, hemicellulases, amylases and proteases within F o r R e v i e w O n l y 4 amylases and pectinases has been studied (Inglis et al 2000;Valášková et al 2007;Baldrian and Valášková, 2008;Younes et al 2011). And even when white rot basidiomycetes are well known producers of enzymes that degrade the main cell wall components (Zaldrazil et al 1995;Elisashvili et al 2008a;Lynch et al 2014), they have not been explored enough as a source of enzymatic extracts for the elaboration of additives in animal feed.…”

Rapid and Effective Oxidative Pretreatment of Woody Biomass at Mild Reaction Conditions and Low Oxidant Loadings

“…In nature, plant cell walls can be biologically altered, catabolized, or degraded by plant pathogens and saprophytes including basidiomycetes [23], ascomycetes [24], and bacteria [25,26]. The strategies used by these organisms include the release of reactive oxygen species produced by redox-active metals and metalloenzymes [27] as well as the excretion of species-dependent combinations of lignin-modifying oxidoreductases [28][29][30][31], monooxygenases [32], and glycan-acting hydrolases, esterases, and lyases.…”